Most fire suppression sprinkler systems are designed in three categories: light hazard, ordinary hazard, and extra hazard. They are based on a design density calculation.

There are several factors that determine the design density of a sprinkler system such as the codes adopted by a city or village, type of building construction, and the occupancy load or better known as commodities.

For example, a government office space may be designed for a light hazard sprinkler system, or a light manufacturing area could be designed with an ordinary hazard system. Lastly, a large storage area could be designed with an extra hazard system storage based on several variables. Some examples would be:

  • Rack or pallet storage
  • Plastic materials
  • Open box storage

All the variables mentioned have a significant impact on the design and fall under design density that the fire protection engineer puts in the plan review. A sprinkler system is designed to keep a fire in check until the fire department arrives, but if not designed correctly, the fire could overtake the system.

Another area that affects the design is the water distribution main size that comes into the building. Sometimes the water flow calculations are inadequate to meet the code requirements and adjustments need to be made to the system, or a fire pump needs to be added to meet the potential fire flow.

Some questions to ask when looking at your building should be:

  • What type of system does your building have?
  • Is the system inspected and maintained on a regular basis?
  • Does the system have a fire pump?
  • Has the occupancy ever been changed from the original intent of use, and if so, will the current system meet the needs or are changes needed to make to the system sufficient?

For more information on property risk management, contact an MMA Advisor today.

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